Mortgage rates have been at historically low levels for a while now. The benchmark 30-year fixed-rate mortgage has averaged 4.01% over the past 52 weeks

That’s likely to change when the Federal Reserve finally decides to raise the federal funds rate, which has been near 0 for close to a decade. The central bank rate increase is inevitable.

Will rates rise before December?

Interest rates on mortgages may move higher before the first increase of the federal funds rate is implemented, which could be at the meeting in December

Those planning to get into the housing market in 2016 may want to consider a home purchase before the end of the 2015

Higher rates increase the debt-to-income ratios for potential borrowers, which could put some of them out of the running for a mortgage approval.

Debt burden could jump

Debt to income ratios during the first half of 2015 averaged 35.5%. All other things being equal, a .5 increase in rates would bump the average DTI ratio to 37%.

Based on analysis of loan-level ratios for a large sample of loans approved in the first half of this year, as much as 7% of mortgage applicants would have failed to get approval as a result of higher debt-to-income ratios caused by higher rates